1. Field of the Invention
The present invention relates to a magnetic head slider using a giant magnetostrictive material, to a magnetic head assembly provided with the magnetic head slider and to a magnetic disk drive apparatus provided with the magnetic head assembly.
2. Description of the Related Art
In a hard disk drive (HDD) apparatus that is one kind of a magnetic disk drive apparatus, a magnetic head slider attached at a top end section of a head support member having a suspension and a support arm aerodynamically flies with keeping a predetermined space or flying height above the surface of a rotating magnetic disk. In this flying state, a thin-film magnetic head formed on the magnetic head slider performs writing of signals to the magnetic disk using magnetic field generated from an inductive write head element, and performs reading of signals by sensing a magnetic field from the magnetic disk using a magnetoresistive effect (MR) read head element. The magnetic effective distance between these magnetic head elements and the magnetic disk surface is defined as a magnetic spacing.
Recently, a track width of a thin-film magnetic head becomes narrower to satisfy the requirements for increasing data storage capacities and recording densities of the HDD apparatus and also the requirement of downsizing of the HDD apparatus. In order to work around lowering in writing ability and reading ability due to narrowing in the track width, the magnetic spacing of the recent thin-film magnetic head is determined to a very small value of about 10 nm.
U.S. Pat. No. 5,991,113 and U.S. Patent Publication No. US2003/0174430A1 disclose a method for precisely controlling such micro magnetic spacing by forming a heater near or in a head element of a magnetic head slider and by thermally expanding or protruding a part of the head element as required. Such method is called as a thermal pole tip protrusion (TPTP) method.
However, according to the conventional magnetic spacing control technique using the TPTP method, since (1) it is necessary to additionally form a heater within a limited and narrow space of the magnetic head slider, (2) it is necessary to additionally form a heater drive and control circuit in the HDD apparatus, and (3) it is necessary to additionally form on the magnetic head slider a wiring member for electrically connecting the heater and an external circuit, not only the configuration of the magnetic head slider becomes complex causing its design to make difficult and its manufacturing cost to increase but also intrinsic read/write characteristics of the thin-film magnetic head deteriorates. Further, due to heat generation of the heater, unwanted temperature increase in the magnetic head slider may be induced.